1. Field of the Invention
This invention pertains generally to improvements relating to systems for monitoring the activity of patients in hospital rooms, and specifically to a portable single sensor system for detecting the activity of a patient in a hospital bed.
2. Description of the Prior Art
Hospital patients are susceptible to serious injury in slip-and-fall accidents, particularly when attempting to exit their hospital beds. Hospital patients can be better protected from such injuries if hospital personnel could be adequately alerted in a timely manner to assist the patient and in turn hospital patients adequately warned in a timely manner to await assistance.
Hospital bed attachments are known which alert hospital personnel if a patient attempts to exit a hospital bed. U.S. Pat. No. 4,947,152, issued to Hodges on Aug. 7, 1990, discloses a patient monitoring apparatus comprising a detection means installed on a wall of a hospital room, which detection means generates an alert signal in response to presence of a patient in a predetermined zone spaced apart from the hospital bed, such predetermined zone generally includes a predetermined fanshaped zone extending from the detection means across the hospital room above and spaced apart from the hospital bed so the detection means does not respond to normal movement of the patient in the hospital bed.
U.S. Pat. No. 4,228,426, issued to Roberts on Oct. 4, 1980, discloses a patient monitoring apparatus comprising a switch installed in a pad positioned in the bedding of the hospital bed underneath a hospital patient. If the hospital patient gets up from the hospital bed, the switch contacts open, generating an alarm signal.
U.S. Pat. No. 4,196,425, issued to Williams, Jr., et al., on Apr. 1, 1980, discloses a photocell system wherein a plurality of optical energy emitters and photocells are installed in complementary locations on a hospital bed, generally at the head and foot of the hospital bed. If a hospital patient in such a hospital bed sits up or starts to get out of the hospital bed, an energy beam is interrupted and an alarm signal is produced.
Patient monitoring systems such as those disclosed by Roberts and Williams require that a sensing device be installed in the hospital bed and that a cable or other signal transmission means be used to connect said sensing device to an external circuit. Such a cable or other transmission means may pose a hazard to the hospital patient in the hospital bed as well as when the hospital patient is exiting the hospital bed. Such a cable or other transmission means may interfer with the making-up or moving of the hospital bed. Additionally, patient movement in the hospital bed may by itself contribute to a higher rate of false alarms. The patient monitoring system disclosed by Hodges provides a detection means remote from the hospital bed which is generally mounted relatively permanently on a hospital room wall and responds to movement in a predetermined fanshaped zone. Such a predetermined fanshaped zone may detect the presence of others in the hospital room such as when two hospital beds are located in the room and one of the hospital patients therein is receiving visitors or assistance. The predetermined fanshaped zone may not differentiate between single patients and others in the hospital room or movement by a hospital patient not receiving visitors or assistance, especially if the hospital beds are partitioned by means of a moveable partition or the like. Such lack of differentiation may decrease the efficiency and utility of such an apparatus.
Those skilled in the art are aware of the need for a simple, relatively inexpensive improved portable patient monitoring system remote from the hospital bed, which system monitors separate hospital beds and provides an alert to a nurses station as well as to the patient if the patient attempts to exit the hospital bed.
Therefore, it is an object of the present invention to provide a simple, relatively inexpensive improved portable patient monitoring system remote from the hospital bed, which system monitors separate hospital beds and provides an alert to a nurses station as well as to the patient if the patient attempts to exit the hospital bed.